Torque converter for a vehicle

Abstract

A torque converter including a stator rotatable about an axis and having a stator hub, and a thrust bearing mounted to the stator hub. The stator hub has a recessed portion that is recessed from one axial end face of the stator hub. The thrust bearing includes a bearing race received by the recessed portion of the stator hub. A coupling connects the bearing race with the stator hub. The coupling includes a first engaging part disposed on an outer periphery of the bearing race and a second engaging part engaged with the first engaging part and disposed on an outer periphery of the recessed portion in opposed relation to the outer periphery of the bearing race. The first and second engaging parts cooperate to prevent a relative rotation between the bearing race and the stator.

What is claimed is: 
     
       1. A torque converter comprising: a stator rotatable about an axis, said stator including a stator hub having an end wall extending radially inwardly at an axial end of said stator hub, said end wall being formed with a recessed portion recessed from one axial end face thereof;   a thrust bearing including a pair of first and second bearing races opposed to each other and a plurality of rollers disposed between said first and second bearing races, said first bearing race being received by said recessed portion; and   a coupling connecting said first bearing race with said stator hub;   said coupling including a plurality of projections extending radially outwardly from an outer circumferential surface of said first bearing race and arranged in a circumferentially spaced relation to each other and a plurality of grooves that is engaged with said plurality of projections, said plurality of grooves extending radially inwardly from an outer circumferential surface of said recessed portion that is opposed to said outer circumferential surface of said first bearing race and being arranged in a circumferentially spaced relation to each other, said plurality of projections and said plurality of grooves cooperating to prevent a relative rotation between said first bearing race and said stator.   
     
     
       2. A torque converter as claimed in claim 1, further comprising a one-way clutch enabling said stator to rotate in one direction, said one-way clutch being disposed within a clutch-receiving portion formed in said stator hub, said one-way clutch including an outer race formed with serrations on an outer circumferential surface thereof, said outer race being in fitting engagement at the serrations with said clutch-receiving portion. 
     
     
       3. A torque converter as claimed in claim 2, wherein said outer race has a chip trapping groove disposed adjacent to said serrations, said chip trapping groove trapping chips abraded from said stator hub upon said outer race being press-fit into said clutch-receiving portion. 
     
     
       4. A torque converter as claimed in claim 3, wherein said outer race is made of a material harder than a material of which said stator hub is made. 
     
     
       5. A torque converter as claimed in claim 2, wherein said one-way clutch includes a sprag inside said outer race and said outer race has a radially extending projection on an axial end portion thereof, said projection abutting against said sprag to prevent said sprag from being axially offset relative to said outer race. 
     
     
       6. A torque converter as claimed in claim 2, wherein said end wall of said stator hub has an opposite axial end face partly defining said clutch-receiving portion, said outer race of said one-way clutch abutting on said opposite axial end face of said end wall. 
     
     
       7. A torque converter as claimed in claim 2, wherein said plurality of rollers have a rolling diameter greater than an inner diameter of said outer race of said one-way clutch. 
     
     
       8. A torque converter comprising: a pump impeller;   a turbine opposed to said pump impeller;   a stator interposed between said pump impeller and said turbine, said stator being rotatable about an axis, said stator including a stator hub having an end wall extending radially inwardly at an axial end of said stator hub, said end wall being formed with a recessed portion recessed from one axial end face thereof;   a thrust bearing disposed between said stator and said turbine, said thrust bearing including a first bearing race received by said recessed portion and a second bearing race opposed to said first bearing race and in contact with said turbine; and   a coupling mutually engaging and cooperating to lock said first bearing race on said stator, said coupling including a plurality of projections extending radially outwardly from an outer circumferential surface of said first bearing race and arranged in a circumferentially spaced relation to each other and a plurality of grooves engaged with said plurality of projections, said plurality of grooves extending radially from an outer circumferential surface of said recessed portion that is opposed to said outer circumferential surface of said first bearing race and being arranged in a circumferentially spaced relation to each other.   
     
     
       9. A torque converter as claimed in claim 8, further comprising a second thrust bearing disposed between said stator and said pump impeller, said second thrust bearing being similar to and substantially aligned with said first thrust bearing along a line parallel to an axis of rotation of said torque converter, said second thrust bearing including a third bearing race arranged at an opposite axial end of said stator hub and a fourth bearing race opposed to said third bearing race and in contact with said pump impeller. 
     
     
       10. A torque converter as claimed in claim 9, further comprising a one-way clutch enabling said stator to rotate in one direction, said one-way clutch being disposed within a clutch-receiving portion formed in said stator hub, said one-way clutch including an outer race formed with serrations on an outer circumferential surface thereof, said outer race being in fitting engagement at the serrations with said clutch-receiving portion. 
     
     
       11. A torque converter as claimed in claim 10, wherein said outer race has a chip trapping groove disposed adjacent to said serrations, said chip trapping groove trapping chips abraded from said stator hub upon said outer race being press-fit into said clutch-receiving portion. 
     
     
       12. A torque converter as claimed in claim 11, wherein said thrust bearing includes a plurality of rollers disposed between said first and second bearing races, said plurality of rollers having a rolling diameter greater than an inner diameter of said outer race of said one-way clutch. 
     
     
       13. A torque converter as claimed in claim 11, wherein said outer race is made of a material harder than a material of which said stator hub is made. 
     
     
       14. A torque converter as claimed in claim 10, wherein said one-way clutch includes a sprag inside said outer race and said outer race has a radially extending projection on an axial end portion thereof, said projection abutting against said sprag to prevent said sprag from being axially offset relative to said outer race. 
     
     
       15. A torque converter as claimed in claim 10, wherein said end wall of said stator hub has an opposite axial end face partly defining said clutch-receiving portion, said outer race of said one-way clutch abutting on said opposite axial end face of said end wall.